Floatable breakwater



Feb. 5, 1952 P. L.. GUARIN FLOATABLE BREAKWATER Filed Oct. 25, 1949 2SHEETS-SHEET l Feb. 5, 1952 p, GUARW 2,584,867

FLOATABLE BREAKWATER Filed oct. 25, 1949 2 SHEETS- SHEET 2 described asbeing orbital in' nature.

Patented Feb. 5, 1952 FLOATABLE BREAKWATER v Paul L. Guarin, Houston,Tex., assigner'A to Shell Development Company, San Francisco, a,corporation of Delaware Application october z5, 1949, serial No'.123,483'

Claims. (C1. 61-'5.)

This invention relates to a floatable breakwater land pertains moreparticularly to a device ,adapted to be positioned at a distance fromoilshore marine installations to break and smooth out waves which wouldotherwise impinge upon e said installations.

Many marine installations, such as offshore well drilling rigs, oifshorewell installations, and the like, must be protected from waveaction,particularly during the period that drilling operations are carried on.Numerous types of break- Waters have been used for this purpose. Sincerigid or immovable breakwaters, of whatever Lconstruction or material,are often fractured, overthrown, undermined, or destroyed in a shorttime bythe persistent force of wave action, and since the cost ofbuilding and maintaining permanent breakwaters is very great, it isdesirable that the breakwaters used around drilling installations be ofthe non-rigid type. In offshore well drilling operations, the drillingequipment may be located at the drilling side only temporarily, i. e.,only while the well is being drilled. After the well is Y completed, theequipment may be moved to another well site. For use with such portabledrilling equipment, it is desirable that protective breakwaters be ofthe portable type in order to facilitate the movement of the breakwaterto a new drilling site. Generally, a protective breakwater is alsopositioned to protect the completed well installation, although asmaller breakwater may be used for this purpose than the one needed toprotect the installation when the well is being drilled.

It is well known that there is both a vertical and a horizontaldisplacement of water particles in a wave action. The verticaldisplacement is due to gravity while the horizontal displacement isgenerally due to wind. Thus, the particles of water on or near thesurface of a water wave move in a circular motion and the wave may beThe yWave form travels swiftly over the water surface, Whereas the waterparticles oscillate back and forth and scarcely advance. The speed ofthe Wave form is known as wave velocity While the speed of the Waterparticles is called orbital velocity. Forces exerted by the Waves onobstacles are primarily due to the orbital motion.

4The orbital velocities are largest at the surface and they decreaserapidly with depth until they cease entirely at a depth equal to thelength of the Wave. As waves reach shallow-water their velocitydiminishes and the circular motion of 'the water particles that existedin deep Water is 15 .waves against marine installations.

-a breakwater composed of a pluralityy Offeadily Aportable units4adapted .to be chained or held together by otherl means andindependently anchored. y, vAnother object of 'thisfinvention is toprovide -a breakwaterY comprising-,a.seriesl of invasie.-v

squeezed to' aneiipucaimbudn duelo] strictiveeffect of theVsealbottor'nl Mostbreakwaters used at presentar either'of -the fixedand rigid type, that act as a complete ,barrier to an entire wave, orofthe floating type that act as .a :drag barrier .for the tops of thewaves. Y

`It is a primary object of the present`l invention to provide abreakwater adapted to be'positioned and anchored `onthe,'oce'a'nflo'oi`- and extending ,upward to-a point nearthe surfaceofv the Water for breaking upl thel orbital "motion of'yfwater Waves,thereby reducing the forces exerted'bythe It is also anobject of` thisYinvention "to provide pervious barriers `anchored below the surfac'ein a.line substantially parallelto that of rthe v"waves,

whereby the wavesfare caused to pass through successive perviousbarriers which successively break down the orbitalmotion of vthewaves- 1A still furtherobject of the. presentinvention ,is to provideoatablebreakwater units which may be floated to and sunk a't anydesiredvlocaition and subsequently.A re-iloated for keasyjtransfer toanotherlocation.

Other objects and advantages willbecoine' apparent from the followingdetaileddescription mtaken with reference to thedrawing, wherein; f

lFigure 1 is a diagrammatic view of two ofthe present breakwater unitsanchored on the ocean loor. I

Figures 2 and 3 are top views, of the breakwater unitsofFigurel.

Figure 4 is a schematic diagram illustrating 4a marine installationprotected by. Vbreakwater barj riers according to the presentinvention.' fj

Referring to Figure lof thedrawi g, breakwater unit of the present.invention mayA comprise a hollow, elongated fluidtight housing orpontoon II having ascreen or vgrid I2 secured to oneside and/or the topthereof by hinge or sup,- port members I3. t The hinge members I3 ar'epreferably adjustable as to length and position whereby the grid I2v maybe fixed at approximately the desired anglewith regard .to .the `housingI I. The pontoon I I has preferablya flat bottom I4 to give it morestability `when it, servevs'fas the base supportefor the gridbarrier l2.Irdesired, the pontoon may be suitably loaded to,

sure that it will always come to rest Awith its bottom on the oceandoor. The hollow pontoon is equipped with fluid inlet and outlet portsI5 and I6, respectively, to which are connected flexible conduits I'land I8. The other end of the conduits Il and I8 may be closed by valvesI and having, couplings ZI and 22 to which may be connected 'ccm'duitsfroma pump or 'air vcompressor carried on a barge for purposes offlooding or emptying the pontoon.

The valved ends of the flexible conduits I1 and I8 are carried by ailoating buoy or Ar'aont'o'on' 2-3, which. because o1' its relativelysmall size and the flexibility of the conduits, 'ofierslittle resistanceto the wave action. If desired, the 'pontoon Il,

when ilooded and positioned on the ocean Iloor 24, may be additionallystabilized by :suitable anchoring means such as anchors and anchoringchains or cables 26 which may be secured 'to Athe pontoon I.I or grid I2inany suitable manner.

The grid' 'oi' screen Irmay be' 'of 'any' suitable sizeand design.Asshowrr in Figure 2, the grid comprise. 'two or more 'support bars 2l'to which 'are secured', at right'angles, a pluralityof substantially'eyenly'spaced crossv bars 2'8'. The bars"21` and' 28 may' be fixedly':secured together in any suitable manner, as by bolting, welding, or thelike, and may be of 'any desired length, shape orV sp'acin'g.Preferably', the open area of the 'grid I2 is 'equal to about one-'halfthe area 'Within'. the periphery' Uf the grid. The grid 5'2 may. bemounted at any' desired angle on top of 'the pontoon I I. The'grid isnormally xedly set at substantially 'at 45 degree angle with thesurfac'e of the' water, as' illustrated in Figure 1, although. it may'deviate 'from such position by at least c30 in each direction,according to circumstanoe's. With the 'grid slanted in the positionshown, the various portions of a `waveV hit and pass through the `gridinfsucc'ession whereby the' grid is not subjected to 'the impact of the'total energy of the' wave at any' one moment.

A's' shown in Figure '2, 'a 'plurali-ty o'i breakwater'uni'ts 'Hand` 30'maybe positioned side by side 'and' secured together and to othersimilar units 'by chains 3| 'and' B2', cables or the like.

it may be seen from the embodiment or the present breakwater'diagiammatically -illustrated in 'Figures iv and '3, that the ba'semember of the breakwater may comprise 'more than one p'ontoon. such aspontoons N and II, 'upon which a 'grid 42 'may be mounted by hinge orsupport members "43. The support members #3 ,are preferably secured to'thepontoons lo and 4I by 4articulated or 'pivot'.ed4 Vconnectiesns 3Bfand 134l to in- 'sure that the grid '4'2 will be at least 30 degrees tohorizontal when the pontoons rest on the ocean nobr. The two pontoons-1band Il may be secured. together by cables -or "chains 4l and theinteriors of said pontoons may bein communication through a hexibleconduit I5 whereby both pontoons may 'Simultaneously ll'lled or emptiedby `pumping air 'or water 'through other flexible conduits I6 and Il.One end of said 'conduits i8I and 'H are normally closed by ivalves "K8'and 49 which are suitably secured to aubuoyjor .pontoon 15b. Ifdesired, the pontoons "40 dhd11 'may more securely anchored `by suitableanchors 5I and anchor chains '5-2 which may 'be amxed to 'any Vpoint onthe pontoons 4a and Il `ofthe grid l2.

As schematically vshown in 'Figure 4, an offshore well drilling'installation may comprise, for Iexainpic,` an operating platform 55, fastorage platform 5I, 'a barge A5f! moored alongside, and/or 'thepontoons are filled with air.

other related equipment well known to the art. In order to protect theinstallation from wave action, a plurality of the present breakwaterunits, as represented at 58, are secured together by cables or chains 59and anchored at a distance from the drilling installation on the weatherside thereof. Preferably, each of the breakwater units58 is suppliedwithindependent anchoring means 60 whereby 'a series of said units maybe anchored in a line, arc, or any vother desired contour at anypredetermined distance from the drilling installation, as shown inFigure 3.

In forming a breakwater barrier, several units are chained or tiedtogether by other means and The series of breakwater units: are thentowed to the desired location where each of the pontoons is ilooded byopening valves I9 and 20 (Figure 2) and introducing water into thepontoons either by pumping or any other means. When pumping is used theooding is accomplished by attaching a hoseV (not shown) to coupling 2lor 22 with the other end of the hose beingl attached to a pump (notshown)l on the barge whereby water may be pumped into said pontoonscausing the breakwater structure to sink to the ocean floor. When thebreakwater unit is in its predetermined position, it may be suitablyanchored.

Preferably, a second breakwater barrier also comprising a number ofbreakwater units, as rcpresented at 59 (Figure 3), Ais towed to and sunkin a line of substantially the same contour as said first breakwaterbarrier and at a distance therefrom. The height of the breakwater units58 and 59 is previously selected or adjusted so that the screen or gridI2 (Figure l) is positioned neai or just below the surface of the water.

As already Astated hereinabove, it is the general purpose ofthis-invention to provide means for the dissipation of Wave energy bystages.

. This is in contrast with permanent bre'akwaters vwhich must be builtsufficiently large to stop the wave motion and dissipate the wave energyin one stage. The grid or screen feature of the present breakwater unitis so designed that a partial, rather than complete, .interference withsubsurface Water movement is effected. 'I'he pervious grids of thepresent breakwater units interfere with the orbital motion of the waves,thereby reducing the 'forces exerted by said waves against a marineinstallation. When the orbital motion of the Waves has been subjected tointerferences a sufficient number lof times by succeeding breakwaterunits, the waves are caused to dissipate most of their energies vbeforereaching the oilshore drilling installation.

If desired, when the marine drilling installation is moved to anotherlocation, the breakwater barriers may be re-ilo'ated -and towed to thenew drilling site. On the' other hand, the breakwater barriers may beleft in position at the completed well installation to act 4as, apermanent breakwater barrier. In re-floating the individual units, anair hose, Aconnected to a compressor and carried by a barge (not shown),may be connected to a coupling 2i (Figure 2). Both valves I9 and 20 arethen opened and compressed air is introduced into the pontoon II untilthe breakwater unit floats. Valves I9 and 20 are Ithen closed and theair hose is disconnected from the coupling 2I. The other breakwaterunits are re-floated in a similar manner. The anchors 25 may bedisconnected from the anchor cables 2E and carried by the barge (notshown) to the new location.

It is to be noted that an especially desirable feature of the presentbreakwater unit is that the valves I9 and 2i) (Figure 2) and thecouplings 2| and 22 of the conduits vl'l and I8 are secured to a buoywhereby they remain above the surface of the Water at all times and arereadily available for flooding and re-oating operations. The length ofthe fiexible conduits l1 and I8 is necessarily at least as great as thedepth of water in which the breakwater unit is located.

I claim as my invention:

1. A floatable breakwater unit adapted to be towed to a pre-determinedlocation and sunk on the ocean oor, said breakwater unit comprising anelongated nat-bottom uidtight pontoon, a rigid water-pervious gridmember, pivoted support means adjustable as to length and angularposition for securing said grid member to said pontoon, said grid memberprojecting substantially upwardly from said pontoon at substantially a45 degree angle to the horizontal to a point near the ocean surface,port means in said pontoon whereby a liquid and a gas may be alternatelyintroduced for sinking and floating said breakwater unit, flexibleconduitl means having one end thereof connected to said port means,coupling means at the other end of said conduit means, valve means insaid conduit means adjacent said coupling means, and a buoyant memberaiiixed to said conduit means for supporting said coupling and valvemeans above water at all times.

2. A iioatable breakwater unit adapted to be towed to a pre-determinedlocation and sunk on the ocean floor, said breakwater unit comprising anelongated fluidtight pontoon, a rigid grid member, articulated meansconnecting said grid member to said pontoon, whereby said grid member iscaused to assume an angle of at least 30 degrees to the horizontal whensaid pontoon rests on the ocean door, port means in said pontoon wherebya liquid and a gas may be alternately introduced for sinking andiioating said breakwater unit. iexible conduit means having one endthereof connected to said port means, coupling means at the other end ofsaid conduit means, valve means in said conduit means adjacent saidcoupling means, and a buoyant member aixed to said conduit means forsupporting said coupling and valve means above water at all times.

3. A oatable breakwater unit adapted to be towed to a pre-determinedlocation and sunk on the ocean oor, said breakwater unit comprising anelongated flat-bottom fiuidtight pontoon, a rigid water-pervious gridmember, pivoted support means adjustable as to length and angularposition for securing said grid member to said pontoonl said grid memberprojecting substantially upwardly from said pontoon at substantially a45 degree angle to the horizontal to a point be low the ocean surface,port means in said pontoon whereby a liquid and a gas may be alternatelyintroduced for sinking and iioating said breakwater unit. flexibleconduit means having one end thereof connected to said port means,coupling means at the other end of said conduit meansl valve means insaid conduit means adjacent said coupling means, a buoyant member amxedto said conduit means for supporting said coupling and valve means abovewater at all times, anchoring means carried by said breakwater unit andadapted to be sunk therewith, and flexible cable means securing saidanchoring means to said pontoon.

4. A floatable breakwater unit adapted to be towed to a pre-determinedlocation and sunk on the ocean floor, said breakwater unit comprising apair of elongated fiat-bottom iiuidtight pontoons, a rigidwater-pervious grid member, pivoted support means adjustable as tolength and angular position for securing said grid member to saidpontoons, said grid member projecting substantially upwardly from saidpontoons at substantially a 45 degree angle to the horizontal to a pointbelow the ocean surface, port means in said pontoons whereby a liquidand a gas may be alternately introduced for sinking and floating saidbreakwater unit, flexible conduit means have ing one end thereofconnected to said port means, coupling means at the other end of saidconduit means, valve means in said conduit means adjacent said couplingmeans, a buoyant member affixed to said conduit means for supportingsaid coupling and valve means above water at all times, anchoring meanscarried by said breakwater unit and adapted to be sunk therewith, andflexible cable means securing said anchoring .means to said pontoons andto said grid member.

, PAUL L. GUARIN.

REFERENCES CITEI)` The following references are of record in the file ofthis patent:

UNITED STATES 'PATENTS Number Name Y Date 335.032 Leeds 26, 1886 902,372Cameron Oct. 27, 1908 1.004,'718 Wieland Oct. 3, 1911 Ironman PATENTSNumber Country Date 20,072 Great Britain o! 1894;

